Electronic systems produce and are susceptible to electromagnetic interference (EMI), created through either electromagnetic induction or electromagnetic radiation from an external source. In the context of radio waves, radio frequency interference (RFI), is produced. The interference created has the potential to interrupt, deteriorate, or cause other unwanted performance in many common devices ranging from radios to cellular phones to televisions. Federal Communications Commission (FCC) requirements for the mitigation RFI are extremely strict, down to microvolts, thus it is important RFI be mitigated using appropriate radio frequency (RF) grounding.
To suppress RFI radiation, many enclosures are designed to form a sealed container for whatever may be producing the RFI. For example, an integrated circuit (IC) chip generating radio frequencies for a plasma lighting system may be contained within a housing that is sealed using the correct RFI gaskets. What is more difficult is the containment of RFI that escapes through the bulb of a lighting system that uses radio waves, i.e. plasma lighting. To contain the RFI produced from the light source, complicated housings, referred to from here on as “RFI Boxes”, must be employed to contain the escaping radiation. Conventional hardware required to successfully contain RFI from a light source as described above includes a sealable cavity to which the light source is attached, a gasket, and a piece of glass which is sealed against the gasket using a fastened flange.
However, these additional materials add cost to the production process as well as time to assembly. Moreover, present RFI boxes cause a loss of total electromagnetic output per area of coverage i.e. watts per square meter, also known as irradiance. Irradiance comprises not only the visible spectrum, but UVB and infrared wavelengths as well. Additionally, glass reduces output by an additional eight percent, and blocks the beneficial UV wavelengths UVA and UVB. Some plasma technologies produce UVC, which demands the use of glass to filter this wavelength out which can cause damage on the cellular level.
Aside from these concerns, the geometry of conventional RFI boxes for lamps causes coverage area to be diminished considerably, requiring increased distance from a desired coverage plane to reach a desired coverage area. For example in terms of horticulture, coverage of a 4 foot by 4 foot area should be achievable at 12 to 18 inches from the desired plane, i.e. the canopy, to produce adequate intensity for growth. When using a conventional RFI box, this distance must be increased dramatically, causing output at the desired plane to be less than optimal.